Fixation device and method for installing same

ABSTRACT

A fixation device and apparatus for inserting the fixation device securely into a bore in an element, e.g. bone. The apparatus is a hand held device having an actuating mechanism and a longitudinally extending member coupled to the hand held device adapted to hold the fixation device at a distal end. The fixation device has a plurality of engaging members adapted to be moved outwardly when the fixation device is inserted into the bore to secure the fixation device in the bore. The extending member has an operating member coupled to the fixation device for exerting a force on the fixation device tending to cause the engaging members to extend outwardly to engage the wall of the bore. The operating member is releasably coupled to the fixation device so that once the fixation device is installed, the hand-held insertion apparatus can be removed. In one embodiment, the fixation device is releasably held by a forceps of the hand held device. In another embodiment, the fixation device is releasably held by a coupling member having a frangible connection adapted to break upon experiencing a preset tensile stress.

This is a division of pending application Ser. No. 08/426,715, filedApr. 21, 1995 now U.S. Pat. No. 5,843,127.

BACKGROUND OF THE INVENTION

The present invention relates to fixation devices, and in particular,fixating devices for insertion into bores in materials to allow theconnection of another element to the material in which the fixation isdisposed. In particular, the present invention relates to a fixationdevice for the medical field, which can be inserted into, for example, apre-drilled bore in bone, to allow the connection to the bone of anothermember, for example, a prosthetic member. Alternatively, the fixationdevice can have sutures attached that allow the suturing of anothermember to the fixation device. As an example, the fixation device of thepresent invention may have sutures attached thereto which allow thesecurement of a prosthetic device or artificial member, or a naturalanatomical member, for example, ligaments, to the bone.

Although the present invention has particular application in the medicalfield, it is not limited thereto and may find other uses, i.e., whereverit is necessary to fasten two or more members together, especially whenthe members are to be secured together with fixation devices located inbore holes that are blind or open to only one side, i.e., not completelydrilled through.

U.S. Pat. No. 5,268,001 to Nicholson et al. relates to a bone fastenerfor fixing either a suture or a rivet within a pre-drilled bone hole. Inthe device of that reference, the bone fastener includes an expandablesleeve having an axial bore and a pin which is forcibly insertable intothe axial bore. The expandable sleeve is configured to be insertableinto the bore drilled in the bone and at least a portion of the pin hasan outer diameter greater than the inner diameter of at least a portionof the axial bore of the sleeve. The fastener is emplaced by insertingthe sleeve into a pre-drilled hole in the bone and then forcing the pininto the axial bore of the sleeve, so that the wider portion of the pinpresses outwardly against and expands the narrow portion of the sleeve,causing the sleeve to forcibly contact the walls of the bone hole andfixing the pin and sleeve firmly in place within the hole. The apparatusfor emplacement of the fastener includes a holder for holding theexpandable sleeve in position within the pre-drilled hole in the boneand a plunger moveable in relation to the holder for forcing the pininto the bore of the sleeve so that the pin can be forced in the axialbore without imposing substantial force toward or away from the bone.The device includes a severable attachment between the holder and theexpandable sleeve which is cut by a cutting edge of a cylindrical blade.The sleeve is thereby separated from the holder body and the fullyexpanded and fixed fastener is freed from the insertion apparatus.

The device of the Nicholson et al. reference has several drawbacksincluding that a force must be applied toward the bone or member inwhich the fastener is being inserted. This causes greater strains thannecessary to the patient because the anchor must be expanded by thispushing force, which causes undue strain on the material of the memberin which the fastener is being inserted. The expandable sleeve also maynot provide sufficient engaging force to secure the fastener in the borehole in the bone because it only expands and frictionally engages in thebone without actually cutting or penetrating into the bone.Additionally, the cutting edge necessary to separate the fastener sleevefrom the holder body creates additional complexity.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a fixating device.

It is yet still a further object of the present invention to providesuch a fixating or fastening device which is suitable for insertion intoa pre-drilled hole in a material, e.g., bone.

It is yet still a further object of the present invention to providesuch a fixation or fastening device which can be used to fasten oneelement to another element in which the fixation or fastener device isinserted.

It is yet still a further object of the present invention to provide afixation or fastening device which can be inserted into a material, forexample, bone, to allow the connection of another member, for example, aprosthesis, or which has sutures coupled thereto for the connection ofanother body part, for example, ligaments, to the bone.

It is yet still a further object of the present invention to provide afixating or fastening device which is relatively simple and convenientto use, and furthermore, which is simple to manufacture.

It is yet still a further object of the present invention to provide afixation or fastening device which avoids the need for complicatedcutting mechanisms to sever the fixation or fastening device from itsinsertion apparatus.

It is yet still another object of the present invention to provide anapparatus for inserting a fixation or fastener device into a pre-drilledhole in a member, for example, bone.

It is yet still a further object of the present invention to provide anapparatus for inserting a fixation or fastening device of the typegenerally disclosed in applicant's co-pending application Ser. No.08/294,067 filed Aug. 22, 1994.

It is yet still another object of the invention to provide a fixationdevice that is conveniently loaded into its insertion apparatus.

The above and other objects of the present invention are achieved by anapparatus for inserting a fixation device securely into a bore in anelement comprising a hand held device having an actuating mechanism; alongitudinally extending member coupled to the hand held device adaptedto hold the fixation device at a distal end; the fixation device havinga plurality of engaging members adapted to be moved outwardly when thefixation device is inserted into the bore to secure the fixation devicein the bore; the extending member having an operating member coupled tothe fixation device for exerting a force on the fixation device to causethe engaging members to extend outwardly to engage the wall of the bore;and the operating member being releasably coupled to the fixationdevice.

The objects of the present invention are furthermore achieved by afixation device assembly for engagement by an insertion tool forinserting the fixation device assembly into a bore in a member, theassembly comprising a first member having a plurality of engagingmembers, the engaging members being adapted to be engaged by a camsurface to cause the engaging members to move outwardly to engage thebore in response to actuation by said insertion tool; and a secondmember extending longitudinally from the first member adapted to have aforce releasably exerted thereon for causing the engaging members of thefirst member to engage the cam surface and move outwardly.

The objects of the invention are also achieved by a method for insertinga fixation device securely into a bore in an element comprisingproviding a hand held device having an actuating mechanism; inserting afixation device into a longitudinally extending member of the hand helddevice at a distal end, the fixation device having a plurality ofengaging members adapted to be moved outwardly when the fixation deviceis inserted into the bore to secure the fixation device in the bore;exerting a force on the fixation device with the actuating mechanism tocause the engaging members to extend outwardly to engage the wall of thebore; and releasing the fixation device from the longitudinallyextending member.

Other objects, features and advantages of the present invention willbecome apparent from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail in the followingdetailed description with reference to the drawings in which:

FIG. 1 shows an apparatus for inserting a fixation device or fastenerinto a pre-drilled hole in a member, for example, bone;

FIG. 2 is an enlarged view of the tip of the insertion apparatus shownin FIG. 1 with the fixation device having sutures connected theretoprior to insertion into a bore in a body member;

FIG. 3 is a cross-section through the tip of FIG. 2 rotated by 90° andprior to activation of the fixation device in a pre-drilled bore in abody member;

FIG. 3A is a side view of the fixation device shown in FIG. 3;

FIG. 4 shows a cross section of the tip of the insertion apparatus andfixation device of FIG. 3 after the fixation device has been activatedinto its engaging state;

FIG. 5 shows a cross section of the tip of the insertion apparatus andthe fixation device after the fixation device has been separated fromthe insertion apparatus;

FIG. 6 shows a second embodiment of the present invention showing adetachable holding device for insertion of a variant of the fixationdevice of the present invention which has a frangible connecting pointto the holding device so that the fixation device can be separated fromthe holding device once insertion is complete;

FIG. 7 shows the fixation device according to the device of FIG. 6 withthe cylindrical cover of the holding device removed, for clarity;

FIG. 8 is a perspective view of the embodiment shown in FIG. 6;

FIG. 9 is a side view of a third embodiment of the fixation device ofthe present invention;

FIG. 10 shows an fixation device according to the present inventionwhich has been modified to reduce the amount of stress that the fixationdevice provides to the member in which it is secured;

FIG. 11 shows another modification of the fixation device according tothe present invention;

FIGS. 12, 13 and 14 show one embodiment of the fixation device disclosedin Applicant's co-pending application Ser. No. 08/294,067, generallyshowing the structure of the fixation device employed in thisapplication; and

FIG. 15 shows one embodiment of a detachable coupling device coupling afixation device assembly to its insertion device.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

With reference now to the drawings, FIGS. 12, 13 and 14 generally showthe type of fixation device which is described in Applicant's co-pendingapplication Ser. No. 08/294,067 filed Aug. 22, 1994 and to which thepresent application generally relates and of which the presentapplication is an improvement thereon.

FIG. 12 generally shows the type of fixation device described in theinstant application comprising a two-piece fastener comprising pieces150 and 160, each of which has a group of longitudinally directedfingers 155 and 165 which are distributed circumferentially around therespective fasteners 150, 160. The fingers 155 and 165 interdigitate, asshown in FIG. 13, which shows the fixation device prior to insertion.Once inserted into a bore, for example, a bore in bone, the two portions150 and 160 of the fastener are moved relatively together, causing theinterdigitated fingers to expand outwardly against each other due to thecam surfaces on the opposite member, as shown in FIG. 14. The extendedfingers securely engage the walls of the bore in which the fixationdevice is disposed, providing a secure attachment point. The fingers 155and 165 may have sharp tips for digging into the wall of the bore hole.The insertion tool, which is shown schematically in these Figures anddesignated with the reference numerals 180, 190 and 200, is thenremoved, leaving the fixation device in place and the sutures 170extending from the bore in which the fixation device is disposed. Thefixation device shown in FIGS. 12, 13 and 14 and to be describedgenerally herein may be made of any biocompatible material, for example,a suitable plastic material or a suitable biocompatible metal, forexample, a stainless steel. Although sutures are shown connected to theanchor in FIGS. 12 to 14, the fixation device could also have any othersuitable attaching means, e.g., a threaded hole or post for theattachment of some other member, e.g., a prosthetic device.

In the embodiment shown in FIGS. 12, 13 and 14, the two members 150 and160 of the fastener are drawn together by providing a force on thecollar 200 while holding member 160 fixed, which forces the member 150toward the member 160, thereby flexing and extending the fingers 155 and165 radially outwardly and each pointed in opposite directions. Theextended fingers frictionally grasp the bore in which they are insertedor cut into the interior surface of the bore to hold the fastenersecurely therein. The fingers 155 and 165 may be formed such that theirtips are sharpened, to facilitate the securement of the fixation devicein the bore. The extension of the fingers 155 and 165 pointed along thetwo opposite directions provides a secure attachment of the fastener inthe bore, i.e., the extension of the fingers 155 and 165 pointed alongtwo opposite directions both prevents the fastener from moving furtherinwardly into the bore (if the bore has a further extension), andprevents the fixation device from being pulled out of the bore.

The present invention is an improvement on the fixation device andinsertion devices shown generally in FIGS. 12, 13 and 14 and describedin Applicant's copending application.

As shown in FIGS. 1-5, which show an embodiment of a fixation device andits insertion device according to the present invention, the inventiongenerally comprises an insertion apparatus generally designated 10 whichmay comprise an insertion device 2 which includes a pistol-like grip 3and an actuating lever 4. Extending from the body of the insertion gun 2is a cylinder 5 shown in greater detail in FIGS. 2, 3, 4 and 5. Thecylinder 5 provides a housing for a shaft 6. Both the cylinder and shaftare mechanically operated by the lever 4. The shaft 6 is coupled to theactuating lever 4 such that it is slidable within the cylindrical sleeve5. At a distal end 8, the cylindrical sleeve includes a longitudinallyextending slide opening 9 having a pin 10 slidable therein. The pin 10is fixed in bores 12 provided in the shaft 6. The pin 10 is tightlyfitted into shaft 6 and slidable through members 14 and 16 of a forceps,generally designated 15. At the distal end of the forceps 15, a fixationdevice 17 of the type generally described in applicant's co-pendingapplication is disposed. The fixation device is shown in FIG. 3a in aview corresponding to that shown in FIG. 2. The fixation device 17includes two sections 17A and 17B having interdigitatedlongitudinally-extending engaging members of fingers, as described withrespect to FIGS. 12, 13 and 14. The fingers can take any shape so longas they provide the function of engaging into a borehole once extendedoutwardly. Extending through the interior of the fixation device 17 is abolt 19, which has an opening 20 therein that receives the engagingprongs 22 and 24 of the respective forceps members 14 and 16. As shownin FIG. 3, the forceps 15 is kept in a closed condition (holdingfixation device 17) against the action of a spring 32 by virtue of itsengagement at its head end 25 in a reduced diameter portion 26 of thecylinder 5.

In order to operate the device and insert the fixation device 17 into apre-drilled hole in a member, for example, a hole in bone, the usergrasps the pistol-like insertion device 2 and inserts the tip, havingthe fixation device 17, into the opening in the bone. The lever 4 isthen operated, pulling the lever toward the pistol grip 3. This causesthe shaft 6 to move in the direction of arrow 28 as shown in FIG. 4. Thepin 10 slides in the longitudinally extending hole 9 as shown in FIG. 4.The pin 10 is prevented from moving further by the limit stops providedby the guide opening 9. The movement of shaft 6 has the effect of movingbolt 19 coupled to it in the same direction, causing fixation devicemember 17B to abut the cylinder 5 at 27. The further movement of shaft 6and thus bolt 19 then causes members 17A and 17B to move toward eachother, thereby causing the fingers attached to members 17A and 17B tomove outwardly, as shown in FIG. 4, into engagement with the wall of thebore hole, not shown. The orientation of the fingers may be somewhatexaggerated in FIGS. 4 and 5 for clarity. The fixation device 17 is nowsecurely emplaced in the bore hole, not shown, although still attachedto the insertion apparatus.

When the pin 10 reaches the extent of its travel, upon further actuationof the lever 4, cylinder 5 is then actuated to cause it to move in thedirection of arrows 30 (FIG. 5). Prior to movement of the cylinder 5,the ends 14A and 16A of the forceps portions 14 and 16 remain in theportion 26 of reduced diameter of the cylinder 5, as shown in FIG. 4.Upon further movement of the operating lever 4, and thus movement of thecylinder 5, the cylinder 5 moves in the direction of arrows 30, causingthe reduced diameter portion 26 to ride off the portions 14A and 16A ofthe respective forceps portions 14 and 16, as shown in FIG. 5. Thisallows spring 32 under compression disposed in an opened area 34 betweenthe forceps members 14A and 16A, to expand, forcing the forceps portions14 and 16 away from each other. This frees the fastener 17, with thebolt 19 attached, from the forceps 15 of the insertion device. Theinsertion device can now be removed, leaving the fastener 17 and bolt 19securely in place in the bore in the bone. The fastener 17 and bolt 19,with sutures, generally designated 36, attached, is now securelyembedded in the bore in the bone by virtue of the extension of thefingers of members 17A and 17B, which now firmly grasp the opening inthe bone. Depending upon the material in which it is inserted, and theshape of the fingers on fastener members 17A and 17B, the fingers mayactually cut into the material in which they are secured or may providea frictional engagement. Also, the bolt 19 is securely held in themembers 17A and 17B due to the compression of the inner diameter of themembers 17A and 17B caused by the force of the extended finger impactingagainst the wall of the bore in the bone.

The embodiment of FIGS. 1-5 shows a fixation device or fastener 17 andseparate bolt 19. The bolt 19 can be made part of one of the portions17A of the fixation device or it can be made, as shown, as a separatepart. Furthermore, the sutures 36 may be fastened to the bolt 19 or maybe fastened to the portions 17A. Additionally, the fastener shown inFIGS. 1-5 shows sutures attached thereto which can be used, for example,to attach a ligament or other member to bone. The fastener 17 can justas well be used as a rivet or screw attachment in which case it may havea screw or other hole therein or have a post for attachment of anothermember thereto, for example, a prosthesis.

Although the fastener shown in FIGS. 1-5 has portions 17A and 17B whichhave fingers that point in opposite directions, and which provide twoway securement of the fixation device in the member in which it issecured, the fastener may have fingers which extend only in onedirection, and preferably in a direction preventing pulling of thefastener out of the bore. This is shown, for example, in FIG. 9, whichshows a fastener 17C which includes fingers 17C′. The fastener 17C iscaused to move to the position shown in phantom in FIG. 9, therebyembedding itself in a bore in a member in which it is secured when apulling force 38 is applied. Unlike the fastener 17 shown in FIGS. 1-5,however, because there are no opposed fingers pointing in the oppositedirection, a cam surface 40 on cylinder 55 may be provided so that thefingers 17C′ can be forced to move outwardly. Thus, when pulling force38 is exerted on the fastener 17C, it moves in the direction of arrow 38while simultaneously, the engagement of each finger 17C′ against the camsurfaces 40 causes the fingers to move outwardly into engagement withthe bore hole. Alternatively, the cam surface can be located on thefixation device, instead of on cylinder 55. Further, the cylinder 55 mayalso subject the fixation device to a pushing force, instead of apulling force to fasten the fixation device.

FIGS. 6, 7 and 8 show an alternative embodiment of the presentinvention. In this embodiment, the insertion device includes a cylinder55 having a rod 57 slidable therein. The rod 57 is provided with agraspable end 59 which is grasped by an insertion device 2 of the typeshown in FIG. 1, and not shown in detail. The insertion device of thetype shown in FIG. 1 pulls the shaft 57 in the direction of arrow 60while simultaneously holding the cylinder 55 in position, as shown bythe shading 62 in FIG. 6. The shaft 57 near its distal end has a boretherethrough in which a pin 64 is inserted. The pin 64 couples the shaft57 to a coupling shaft 66. The pin 64 is slidable in a longitudinalopening 65 in cylinder 55. Another pin 68 slidably engages in an opening69 in the shaft 66, which may be formed integrally with bolt 19′. Thebolt 19′ extends through the interior of fixation device 17′ which isformed from two portions 17A′ and 17B′, as in the embodiment of FIGS.1-5. Sutures 36 may be attached to the bolt 19 or the fastener 17′.

Upon the application of force in the direction of arrow 60 to shaft 57,fixation device 17′ is drawn toward cylinder 55. Upon making contactwith cylinders 55 at 56, member 17B′ is prevented from moving. Member17A′, due to the continuing movement of bolt 19′, however, is forcedinto member 17B′, causing the fingers of members 17A′ and 17B′ to moveoutwardly, securing the fixation device 17′ in the bore hole.

Unlike the embodiment shown in FIGS. 1-5, however, the shaft 66 includesa frangible connection 70 which comprises a portion of the shaft 66having an area of increased weakness, e.g., a groove or slit 70 whichcauses the shaft 66 to break upon the application of a specifiedpressure, in the embodiment shown, a tensile force. The tensile force isgreater than the force necessary to form the fixation device 17′ intoits engaging state. The frangible connection point 70 may be, forexample, a reduced thickness area of the fork 66 which is designed torupture at the specified pressure. Upon rupturing, the insertion devicemay be removed from the fixation device, thereby leaving the fixationdevice, with the fingers extended and engaging securely in the borehole, and the bolt 19′ in place in the bore in the member in which thefastener is secured.

FIG. 15 shows one embodiment for attaching shaft 66 to shaft 57 via pin64. Preferably this attachment is releasable so the user canconveniently load a fixation device 17′, with bolt 19′ having shaft 66attached, as an assembly to the insertion device. As shown in FIG. 15,the releasable coupling may take the form of a bayonet coupling,although other equivalent convenient releasable coupling devices can beemployed. To insert the fixation device assembly into the insertiondevice, pin 64 is first guided through an opening 69 in shaft 66, slidinto the bore of the cylinder 55 into the slots 58 while also guided inslot 65, shaft 57 is then turned to secure shaft 66 to shaft 57 with pin64 being seated in portion 58A of the bayonet slots 58.

FIGS. 10 and 11 show alternative embodiments of the fixation devicesshown both in FIGS. 1-5 and in FIGS. 6-9. FIGS. 10 and 11 show thefixation devices (with engaging finger elements in extended positionsand exaggerated for effect) in place in bores in materials 80. In theexample shown in FIG. 10, the material 80 is a longitudinally extendingobject extending in a direction shown by the arrow 81. It is relativelynarrow and accordingly, it is important that the material 80 not bestressed along the thin portions 82 on either side of the bore hole intowhich the fastener 17″ is inserted. Accordingly, the fingers of fastener17″ near the portions 82 can be made shorter so that they reduce thestress applied to the portions 82 of the material. As shown, the fingersnear the stronger areas 84 may be made longer.

FIG. 11 shows another embodiment in which a bore is made close to a side85 of the material 80. In this case, no fingers are provided on the sideof the fixation device 17′″ near the weaker area 82. Thus, it is notnecessary that the fingers be spaced equiangularly about the fixationdevice. Accordingly, the fastener of the present invention may beadapted, as necessary to the particular application, thereby to preventdamage to the underlying material 80 when there is a likelihood that thestress caused by the fixation device may break the material into whichit is inserted. In addition to changing the length and spacing ofselected fingers, other modifications can be made to the fixation devicedepending on the circumstances.

The fixation device of the present invention may be provided to users asa one-time use-disposable assembly. For example, in the embodiment ofFIGS. 1-5, the fixation device assembly comprising fixation device 17and a bolt 19 can be provided to users for use with the insertionapparatus.

In the embodiment of FIGS. 6-8, the assembly comprising only thefixation device 17′ and bolt 19′ including coupling shaft 66 withfrangible connection 70 can be provided as a unit. Alternatively, theassembly comprising what is shown in FIGS. 6 or 8 can be provided as aunit, i.e., bolt 19′ with shaft 66, fixation device 15 portion 17′,cylinder 55 and shaft 57. This entire unit can be packaged as a one-usedisposable member. After the frangible connection 70 ruptures leavingthe fixation device fixed in place, the entire assembly is discarded anda new one inserted into the hand held insertion device. The ball-shapedend 57 provides a snap-fit into the insertion device. In this disposableembodiment, the bayonet connection of FIG. 15 is unnecessary.

As an additional modification, the bolt 19, 19′ can be made integralwith or screwed into or otherwise secured to member 17A, 17A′, in whichcase the head of the bolt can be eliminated.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art.Therefore, the present invention should be limited not by the specificdisclosure herein, but only by the appended claims.

What is claimed is:
 1. A fixation device assembly for engagement by aninsertion tool for inserting the fixation device assembly into a bore ina member, the assembly comprising: a first member comprising a generallyhollow cylinder having a plurality of engaging members, the engagingmembers extending substantially longitudinally in a proximal directionand being adapted to be engaged by a cam surface extending distally tocause the engaging members to move generally radially outwardly toengage the bore in response to actuation by an insertion tool; and asecond member extending longitudinally through the hollow first memberand having a distal head engaging a distal end of the first member andfurther having a proximal end having an engagement portion for receivingan axial non-rotational force applied by a non-rotational element of theinsertion tool releasably exerted thereon for causing the engagingmembers of the first member to engage the cam surface and move generallyradially outwardly into engagement with a wall of the bore; furthercomprising a third member having a plurality of engaging membersextending oppositely to the engaging members of said first member, theengaging members of the first and third members being interdigitated,the cam surface for causing each respective engaging member to extendoutwardly comprising a surface of the respective first and third membersdisposed opposite each respective engaging member.
 2. The assembly ofclaim 1, wherein the second member comprises a center member extendingconcentrically through the first and second member.
 3. The assembly ofclaim 1, wherein the second member is adapted to be engaged by a forcepsof the insertion tool.
 4. A fixation device assembly for engagement byan insertion tool for inserting the fixation device assembly into a borein a member, the assembly comprising: a first member comprising agenerally hollow cylinder having a plurality of engaging members, theengaging members extending substantially longitudinally in a proximaldirection and being adapted to be engaged by a cam surface extendingdistally to cause the engaging members to move generally radiallyoutwardly to engage the bore in response to actuation by an insertiontool; and a second member extending longitudinally through the hollowfirst member and having a distal head engaging a distal end of the firstmember and further having a proximal end having an engagement portionfor receiving an axial non-rotational force applied by a non-rotationalelement of the insertion tool releasably exerted thereon for causing theengaging members of the first member to engage the cam surface and movegenerally radially outwardly into engagement with a wall of the bore;wherein the cam surface comprises a surface of said insertion tool. 5.The assembly of claim 4, wherein the second member comprises a centermember extending concentrically through the first member.
 6. Theassembly of claim 5, wherein the center member is separate from thefirst member.
 7. The assembly of claim 4, wherein the second member hasa frangible connection adapted to rupture when a preset force is appliedthereto.
 8. The assembly of claim 4, wherein the second member isadapted to be received in the insertion tool with a releasableconnection.
 9. The assembly of claim 8, wherein the releasableconnection comprises a bayonet connection.
 10. The assembly of claim 4,wherein one of the first and second members has sutures connectedthereto.
 11. The assembly of claim 4, wherein the second member isadapted to receive a prosthetic device.
 12. The assembly of claim 4,further comprising a fourth member, the fourth member comprising acylinder having a concentric shaft disposed therethrough, the concentricshaft providing the force to said second member, said cylinder havingsaid cam surface.
 13. The assembly of claim 12, wherein the concentricshaft has a snap-in end for removably attaching to the insertion tool.14. The assembly of claim 4, further comprising an insertion tool forinserting said fixation device assembly in the bore.
 15. A fixationdevice assembly for engagement by an insertion tool for inserting thefixation device assembly into a bore in a member, the assemblycomprising: a first member comprising a generally hollow cylinder havinga plurality of engaging members, the engaging members extendingsubstantially longitudinally in a proximal direction and being adaptedto be engaged by a cam surface extending distally to cause the engagingmembers to move generally radially outwardly to engage the bore inresponse to actuation by an insertion tool; and a second memberextending longitudinally through the hollow first member and having adistal head engaging a distal end of the first member and further havinga proximal end having an engagement portion for receiving an axialnon-rotational force applied by a non-rotational element of theinsertion tool releasably exerted thereon for causing the engagingmembers of the first member to engage the cam surface and move generallyradially outwardly into engagement with a wall of the bore; wherein thesecond member comprises a center member extending concentrically throughthe first member; wherein the center member is integral with the firstmember.
 16. A method for inserting a fixation device securely into abore in an element comprising: providing a hand held device having anactuating mechanism for applying an axial force and a non-rotationalmember for transmitting the axial force; loading a fixation device intoa distal end of a longitudinally-extending member comprising saidnon-rotational member, the fixation device comprising a generally hollowcylinder having a plurality of proximally extending engaging membersadapted to be moved generally radially outwardly in response to an axialforce applied by the non-rotational member when the fixation device isinserted into the bore to secure the fixation device in the bore;exerting a force with the actuating mechanism on the fixation device byapplying an axial force to said non-rotational member, thenon-rotational member engaging a shaft provided longitudinally throughthe generally hollow cylinder and having a head at a distal end to causethe engaging members to move longitudinally against a distally extendingcam surface and extend generally radially outwardly to engage the wallof the bore; and releasing the fixation device from the longitudinallyextending member: wherein the step of exerting a force on the fixationdevice comprises providing an axial force on the fixation device tocause the extending members of the fixation device to extend outwardly;wherein the step of exerting a force on the fixation device causesengaging members of the fixation device extending in two oppositelongitudinal directions to extend outwardly.
 17. The method of claim 16,wherein the step of exerting a force on the fixation device comprisesholding the fixation device with forceps while pulling the fixationdevice with the forceps and the step of releasing the fixation devicecomprises releasing the forceps.
 18. The method of claim 17, furthercomprising moving the forceps a preset longitudinal distance whileholding the forceps in a state of engaging the fixation device, therebyto move the engaging members outwardly and then operating the forceps torelease the fixation device therefrom.
 19. The method of claim 18,further comprising providing a center member having an engagement pointfor engagement by the forceps.
 20. The method of claim 16, furthercomprising releasably and removably coupling the fixation device to thelongitudinally extending member.
 21. A method for inserting a fixationdevice securely into a bore in an element comprising: providing a handheld device having an actuating mechanism for applying an axial forceand a non-rotational member for transmitting the axial force; loading afixation device into a distal end of a longitudinally-extending membercomprising said non-rotational member, the fixation device comprising agenerally hollow cylinder having a plurality of proximally extendingengaging members adapted to be moved generally radially outwardly inresponse to an axial force applied by the non-rotational member when thefixation device is inserted into the bore to secure the fixation devicein the bore; exerting a force with the actuating mechanism on thefixation device by applying an axial force to said non-rotationalmember, the non-rotational member engaging a shaft providedlongitudinally through the generally hollow cylinder and having a headat a distal end to cause the engaging members to move longitudinallyagainst a distally extending cam surface and extend generally radiallyoutwardly to engage the wall of the bore; and releasing the fixationdevice from the longitudinally extending member; wherein at least one ofthe engaging members is of a different length than the other engagingmembers.
 22. A method for inserting a fixation device securely into abore in an element comprising: providing a hand held device having anactuating mechanism for applying an axial force and a non-rotationalmember for transmitting the axial force; loading a fixation device intoa distal end of a longitudinally-extending member comprising saidnon-rotational member, the fixation device comprising a generally hollowcylinder having a plurality of proximally extending engaging membersadapted to be moved generally radially outwardly in response to an axialforce applied by the non-rotational member when the fixation device isinserted into the bore to secure the fixation device in the bore;exerting a force with the actuating mechanism on the fixation device byapplying an axial force to said non-rotational member, thenon-rotational member engaging a shaft provided longitudinally throughthe generally hollow cylinder and having a head at a distal end to causethe engaging members to move longitudinally against a distally extendingcam surface and extend generally radially outwardly to engage the wallof the bore; and releasing the fixation device from the longitudinallyextending member; wherein the engaging members are not equiangularlyspaced about the circumference of the fixation device.
 23. A method forinserting a fixation device securely into a bore in an elementcomprising: providing a hand held device having an actuating mechanismfor applying an axial force and a non-rotational member for transmittingthe axial force; loading a fixation device into a distal end of alongitudinally-extending member comprising said non-rotational member,the fixation device comprising a generally hollow cylinder having aplurality of proximally extending engaging members adapted to be movedgenerally radially outwardly in response to an axial force applied bythe non-rotational member when the fixation device is inserted into thebore to secure the fixation device in the bore; exerting a force withthe actuating mechanism on the fixation device by applying an axialforce to said non-rotational member, the non-rotational member engaginga shaft provided longitudinally through the generally hollow cylinderand having a head at a distal end to cause the engaging members to movelongitudinally against a distally extending cam surface and extendgenerally radially outwardly to engage the wall of the bore; andreleasing the fixation device from the longitudinally extending member;wherein the step of exerting a force on the fixation device comprisesproviding an axial force on the fixation device to cause the engagingmembers of the fixation device to extend outwardly; wherein the step ofreleasing comprises providing a coupling member coupling the fixationdevice to the longitudinally extending member, the coupling memberhaving a frangible connection whereby when a preset force in thecoupling member is exceeded, the frangible connection breaks, releasingthe fixation device.
 24. The method of claim 23, wherein the step ofexerting a force on the fixation device comprises providing an axialforce on the fixation device to cause the fingers of the fixation deviceto extend outwardly.
 25. The method of claim 24, wherein the fixationdevice comprises engaging members extending in one longitudinaldirection.
 26. The method of claim 23, wherein the engaging members areequiangularly spaced about the circumference of the fixation device. 27.The method of claim 23, wherein the fixation device has suturesconnected thereto.
 28. The method of claim 23, further comprisingconnecting the fixation device to another member.
 29. The method ofclaim 23, further comprising providing a connector in the fixationdevice for attaching to another member.